Singapore’s central bank said it will consider supervisory actions after DBS Group Holdings Ltd. suffered one of the worst digital disruptions for Southeast Asia’s biggest lender in the past decade.

“This is a serious disruption and MAS expects DBS to conduct a thorough investigation to identify the root causes and implement the necessary remedial measures,” Marcus Lim, assistant managing director at the Monetary Authority of Singapore (MAS), said in an e-mailed response to questions on Wednesday. “MAS will consider appropriate supervisory actions following the investigation.”

The problems in DBS’ digital services — an area where the Singapore-based bank has invested in heavily — started early Tuesday, resurfaced the following day and, to a lesser extent, on Thursday.

“The last few days have underlined the fact that despite the opportunities that fintech provides, banks need to get the basics right,” said Zennon Kapron, managing director at Kapronasia. “Being the ‘world’s best digital bank’ is pretty useless if no one can actually use it.”

The issues stemmed from the bank’s access control servers, resulting in customers’ inability to log in to the services, country head Shee Tse Koon said in a video clip on its Facebook page.

“We acknowledge the gravity of the situation and as we work to resolve matters, we seek your patience and understanding,” Shee said. He apologized to customers and reassured them that their deposits are safe, adding that banking services at all its branches have been extended by two hours.

DBS shares declined 0.9% as of 1:10 p.m. in Singapore Thursday.

Potential Action

The central bank has been following up closely with DBS since the disruptions began, Mr. Lim said. MAS agrees with DBS that the priority is to restore services, he said, without commenting on what potential supervisory actions the authority may take.

Under MAS’s regulations, financial institutions need to ensure that the maximum downtime for each critical system doesn’t exceed four hours within any period of 12 months. In 2010, DBS set aside S$230 million ($168 million) in regulatory capital after its banking services failed for more than six hours following repairs.

DBS in recent years has invested heavily to digitize its core banking business and set up new technology platforms. Such efforts have helped to boost the bank’s return-on-equity and have enabled the lender to reach more customers in all of its markets.

In a separate comment on Twitter, the Singapore-based bank debunked speculation that the disruption was linked to a bond sale by Myanmar’s shadow government set up by supporters of Aung San Suu Kyi, who was ousted by the army in a February coup.

The National Unity Government raised $9.5 million within 24 hours of the opening of the sale of its so-called spring revolution special bonds, Public Voice Television, a channel run by the group, reported Wednesday. The group plans to sell $200 million worth bonds in the initial phase.

Other Glitches 

Singapore has seen other disruptions. In 2018, rival Oversea-Chinese Banking Corp. had a glitch that impacted its automated teller machines and online banking systems for several hours over a weekend.

The outages come as DBS prepares to face new challengers with the arrival of more digital banks in the city-state next year. Grab Holdings, Inc.’s venture with Singapore Telecommunications Ltd. and Sea Ltd. are among four firms that won permits from MAS.

Grab also suffered a technical failure last week, which disrupted its ride-booking services in Singapore and some other Southeast Asian countries. — Bloomberg